Vue-Router懒加载

解决Vue项目过大时，首次进入首页的速度变慢。

第一种：

const routers = [

    {

        path: '/',

        name: 'index',

        component: (resolve) => require(['./views/index.vue'], resolve)

    }

]

第二种：

const Index = () => import(/* webpackChunkName: "group-home" */ '@/views/index')

const routers = [

    {

        path: '/',

        name: 'index',

        component: Index

    }

]

第三种：

const Index = r => require.ensure([], () => r(require('./views/index')), 'group-home');

const routers = [

    {

        path: '/',

        name: 'index',

        component: Index

    }

]